• Applied Microscopy
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• 제46권4호
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• pp.179-183
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• 2016

Mapping brain structural and functional connections through the whole brain is essential for understanding brain mechanisms and the physiological bases of brain diseases. Although region specific structural or functional deficits cause brain diseases, the changes of interregional connections could also be important factors of brain diseases. This review will introduce common neuroimaging modalities, including structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging, and other recent neuroimaging analyses methods, such as voxel-based morphometry, cortical thickness analysis, local gyrification index, and shape analysis for structural imaging. Tract-Based Spatial Statistics, TRActs Constrained by UnderLying Anatomy for diffusion MRI, and independent component analysis for fMRI also will also be introduced.

• Proceedings of the KSMRM Conference
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.37-37
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• 2003

To assess the merits and demerits of postcontrast fat-suppressed (FS) brain MR imaging in children in the evaluation of various enhancing lesions, compared with postcontrast conventional or Magnetization Transfer (MT) imaging. 대상 및 방법： We reviewed patients with enhancing lesion on brain MR imaging who underwent both FS imaging and one of conventional or MT imaging as a postcontrast T1-weighted brain MR imaging. Inclusion criteria of our study were as follows： MR studies should be peformed within one-year interval and showed no significant interval change of imaging findings. Thirty-four patients (21 male, 13 female; mean age, 8 years) with 43 enhancing lesions (19 intra-axial, 19 extra-axial, and 5 orbital location) were included in this study, Twenty-one pairs of FS and conventional imaging, and 15 pairs of FS and MT imaging were available. Two radiologists visually assessed the lesion conspicuity and the presence of flow or susceptibility artifacts in a total of 36 pairs of MR imaging by consensus. For 21 measurable lesions (19 pairs of FS and conventional imaging, 5 pairs of FS and MR imaging), contrast ratio between the lesion and the normal brain( ［SIlesion-SIwater］/[SInormal brain-SIwater]) were calculated and compared.

• Tuberculosis and Respiratory Diseases
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• 제55권5호
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• pp.499-505
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• 2003

Background : The brain is a common site of a metastasis in lung cancer patients. If left untreated, the patients succumb to progressive neurological deterioration with a lower survival rate than with other metastases sites. Contrast-enhanced MR imaging in the absence of symptoms or clinical signs is not recommended for identifying a cerebral metastasis in lung cancer patients because of management effectiveness. This pilot study was performed to estimate whether or not limited brain MR imaging, which has a lower cost, could be used to replace conventional brain MR imaging. Method : Between April 1999 and March 2001, 43 patients with a primary lung cancer and the others (breast cancer, stomach cancer, colon cancer, malignant melanoma etc), who had neurological symptoms and signs, were examined using conventional brain MR imaging to examine brain metastases. The control group involved four patients who had no evidence of brain metastases the sensitivity, specificity and correlation of limited brain MR imaging were compared with conventional brain MR imaging. Results : All the 43 patients who were examined with conventional brain MR imaging showed evidence of brain metastases, whereas limited brain MR imaging indicated that 42 patients had brain metastases(sensitivity=97.67%). One patient in whom limited brain MR imaging showed no brain metastasis had a metastasis in the cerebellum, as shown by the contrast-enhanced T1 weighted axial view using conventional brain MR imaging. The conventional brain MR imaging and the limited brain MI imaging of the 4 control patients both indicated no brain metastases (specificity=100 %). The Pearson Correlation of the two groups was 0.884(Confidence Interval : 99%) observed. Conclusion : Limited brain MR imaging can detect a brain metastasis with the same accuracy. In addition, it is cost-effective (229,000 won, 180$) compared to conventional brain MR imaging(529,000 won, 480$) when patients had neurological symptoms and signs or staging.

• Proceedings of the KSMRM Conference
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.100-100
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• 2003

In brain MR imaging, contrast-enhanced study is important in the detection and characterization of lesions. As a postcontrast brain MR imaging, conventional T1 weighted imaging has been usually used. Magnetization transfer imaging has been used to increase conspicuity of enhancing lesions. In addition, fat-suppression imaging can be used as in other parts of the body. Recently, FLAIR sequence has been reported to be useful in detecting subarachnoid, meningeal, and subdural abnormalities. In this exhibit, we demonstrate basic principles and typical appearances of various pulse sequences that can be used as a postcontrast brain MR imaging in children. Furthermore, we discuss imaging strategies to increase clinical usefulness of postcontrast brain MR imaging for specific abnormalities. The advantages and disadvantages of each pulse sequence are also discussed.

• Korean Journal of Biological Psychiatry
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• 제21권1호
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• pp.1-13
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• 2014

Normal aging causes changes in the brain volume, connection, function and cognition. The brain changes with increases in age and difference of gender varies at all levels. Studies about normal brain aging using various brain magnetic resonance imaging (MRI) variables such as gray and white matter structural imaging, proton spectroscopy, apparent diffusion coefficient, diffusion tensor imaging and functional MRI are reviewed. Total volume of brain increases after birth but decreases after 9 years old. During adulthood, total volume of brain is relatively stable. After 35 years old, brain shrinks gradually. The changes of gray and white matters by aging show different features. N-acetylaspartate decreases or remains unchanged but choline, creatine and myo-inositol increase with aging. Apparent diffusion coefficient decreases till 20 years old and then becomes stable during adulthood and increase after 60 years old. Diffusion tensor properties in white matter tissue are variable during aging. Resting-state functional connectivity decreases after middle age. Structural and functional brain changes with normal aging are important for studying various psychiatric diseases such as dementia, schizophrenia and bipolar disorder. Our review may be helpful for studying longitudinal changes of these diseases and successful aging.

• Journal of Neurogastroenterology and Motility
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• 제24권4호
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• pp.512-527
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• 2018

This review provides a comprehensive overview of brain imaging studies of the brain-gut interaction in functional gastrointestinal disorders (FGIDs). Functional neuroimaging studies during gut stimulation have shown enhanced brain responses in regions related to sensory processing of the homeostatic condition of the gut (homeostatic afferent) and responses to salience stimuli (salience network), as well as increased and decreased brain activity in the emotional response areas and reduced activation in areas associated with the top-down modulation of visceral afferent signals. Altered central regulation of the endocrine and autonomic nervous responses, the key mediators of the brain-gut axis, has been demonstrated. Studies using resting-state functional magnetic resonance imaging reported abnormal local and global connectivity in the areas related to pain processing and the default mode network (a physiological baseline of brain activity at rest associated with self-awareness and memory) in FGIDs. Structural imaging with brain morphometry and diffusion imaging demonstrated altered gray- and white-matter structures in areas that also showed changes in functional imaging studies, although this requires replication. Molecular imaging by magnetic resonance spectroscopy and positron emission tomography in FGIDs remains relatively sparse. Progress using analytical methods such as machine learning algorithms may shift neuroimaging studies from brain mapping to predicting clinical outcomes. Because several factors contribute to the pathophysiology of FGIDs and because its population is quite heterogeneous, a new model is needed in future studies to assess the importance of the factors and brain functions that are responsible for an optimal homeostatic state.

• Korean Journal of Veterinary Research
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• 제52권2호
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• pp.83-87
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• 2012

The study of pigs as a human disease model has been conducted in neuroscience. But the morphological development of pig brain by using MRI is rare. The purpose of this study is to determine whether cerebellum maintains consistent proportion to other brain regions in aging. Clinically healthy sixteen micropigs, 1, 2, 4, and 8 months were studied. The micropigs were anesthetized with isoflorane. MRI was acquired using a 0.3T system. To figure out development of ratio that allowed identification of normal cerebellum size, we measured the area of the cerebellum, brainstem, and forebrain from the mid-sagittal brain images on T1W. Mid-sagittal cross-sectional area (CSA) of total brain, forebrain, brainstem, and cerebellum were expressed as absolute values and also as percentages which were compared between the four age groups of micropigs for the purpose to define the effect of age on brain morphometry. It was found that there was not a significant difference in the percentage of the brain occupied by an individual region between groups although the absolute CSA differed significantly among age groups. There was no effect of age on the ratio between the cerebellum and total brain in 4 age groups. The normal size of cerebellum changes during brain development maintained a consistent ratio to other brain regions in normal micropigs. The ratio of CSA quantified on the mid-sagittal MR images offers a suitable method to detect presence of cerebellar anomalies in micropigs.

• The Korean Journal of Pain
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• 제23권3호
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• pp.159-165
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• 2010

The evolution of brain imaging techniques over the last decade has been remarkable. Along with such technical developments, research into chronic pain has made many advances. Given that brain imaging is a non-invasive technique with great spatial resolution, it has played an important role in finding the areas of the brain related to pain perception as well as those related to many chronic pain disorders. Therefore, in the near future, brain imaging techniques are expected to be the key to the discovery of many unknown etiologies of chronic pain disorders and to the subjective diagnoses of such disorders.

• Journal of the Korean Society of Radiology
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• 제81권3호
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• pp.467-487
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• 2020

Anatomical imaging is the basis of the diagnosis and treatment response assessment of brain tumors. Among the existing imaging techniques currently available in clinical practice, diffusion-weighted imaging and perfusion imaging provide additional information. Recently, with the increasing importance of evaluation of the genomic variation and heterogeneity of tumors, clinical application of imaging techniques using radiomics and deep learning is expected. In this review, we will describe recommendations for magnetic resonance imaging protocols focusing on anatomical images that are still important in the clinical application of brain tumor imaging, and the basic principles of diffusion-weighted imaging and perfusion imaging among the advanced imaging techniques, as well as their pathophysiological background and clinical application. Finally, we will review the future perspectives of radiomics and deep learning applications in brain tumor imaging, which have been studied to a great extent due to the development of computer technology.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1194-1202
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• 2021

Objective: To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. Materials and Methods: In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey's regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. Results: Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. Conclusion: In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.